Electronic textile refers to a system generated by combining conductive textile, a small electronic part, and the like. Here, the conductive textile is generated by applying conductive yarn, conductive ink, and the like to general textile. In a next generation computing research field, research on creating an intelligent object by combining a computing function with an accessory of a textile material such as clothes, bags, or shoes that people wear every day has been actively conducted. Even in the fashion industry, attempts have been made to design a new type of clothes using electronic textile.
A portion of research in the electronic textile field relates to attempts for developing again an existing electronic part that has not been manufactured using a textile material, or mechanical parts using a conductive textile material. Such examples may include a textile button for replacing a mechanical button, a textile-type pressure sensor for replacing a pressure sensor, and the like.
FIGS. 1A, 1B and 1C are diagrams illustrating a tilt sensor proposed by Perner-Wilson according to a related art. As illustrated in FIGS. 1A, and 1B, Perner-Wilson has proposed a tilt sensor shown in a left picture, published in the scholarship conference. The tilt sensor was prepared by disposing six conductive textile electrodes (as shown in FIG. 1A) around a metal bead to be in a circular shape. FIG. 1C is an enlargement showing details of the textile. When the metal bead becomes tilted by inclination, the metal bead becomes in contact with a single electrode (as shown in FIG. 1B) among the above six conductive textile electrodes and thus, it is possible to know an approximate gradient by detecting the contact.
A gradient sensor shown in a right picture proposed by Perner-Wilson was designed to be capable of more consecutively detecting a change in a gradient by employing a potentiometer instead of employing an electrode.
However, the above tilt sensor based on the electronic textile or gradient sensors have many disadvantages. That is, contact occurs only when a metal bead is positioned on the cloth. Therefore, when the metal bead is turned over, it is not possible to know a tilt angle, or there is a need to use two sensors. When a change in a tilt angle occurs in a direction opposite to a direction of a bead, the bead does not move and thus, a malfunction occurs. Since a measurement error of a tilt angle is great, an application field applicable with the tilt sensor constructed as above may be limited.